I had two goals with this project: re-build the 25 year old rear seat and create more storage space in the boat. This generation ProStar is sorely lacking in space. Yes, there's storage in the closed bow, but it's cramped and difficult to access. For a family with two young boys, such limited storage is not acceptable.

The original seat was in rough shape. I didn't take a picture of the cushion before I began, but the vinyl was cracked, split, torn and generally falling apart. The foam in the base was pretty well thrashed as well.

The Styrofoam base had some holes in it and the wood core was rotting. I wasn't too concerned as I was going to be discarding this section of the seat.

Chalk line to mark the cut. I just used a jigsaw to cut the foam. Went smoothly. The chalk is about 6 inches from the bottom of the base.

The point of no return...

Cutting the base off, I lost a lot of structural integrity to the back and sides. I was able to recover most of it by cutting a 'U' out of 3/8" plywood. I used Liquid Nails and 1/4" dowels to glue and pin the plywood to the seat back.

I know it looks bad, and I would have preferred to buy new skins, but that wasn't in the budget. I started cutting down the seat cover and reattached it to the seat back. It looks pretty rough in this picture, but once the seat is in position, you can't really tell.

OK- the next step: seat base and creating more storage. I took a cue from this post about creating more storage under the rear seat by building in a compartment. I enlisted the help of a contractor buddy and creative genius. He had some redwood left from a project, so we ripped it to 5" and built a basic rectangular frame.

With the frame giving us a new height for the seat base, we cut a piece of 5/8" plywood to size and then cut out two large access panels. The plywood was then coated in West System epoxy for strength and waterproofness.

Next step- cushions. I picked up some foam at the local foam shop- I went with a 5x5" high density foam for the front of the cushions and two layers of 2" foam for the main seat. I used a high density foam on top with a medium density underneath. On the left side of the seat is the leftover foam so you can see the different thicknesses and layers.

I went with three cushions, two over the storage access holes and one in the center of the seat that would cover a carpeted step area. I had managed to borrow an industrial sewing machine and had enlisted a friend to help with sewing cushions, but we couldn't get the machine working. The backup plan was we glued the foam to a plywood base (epoxied both sides first) and then wrapped the vinyl over and stapled it. When I say wrapped, we literally wrapped the foam cushions like you'd wrap a present. Turned out well though, I think.

Next step was carpeting the seat box and seat base. That was relatively straight forward. I used marine carpet I sourced through West Marine. I discovered that the original seat back is angled, and under pressure would ride up against the back of the boat. My solution was to cut two pieces of redwood, carpet them and then screw them down to the seat base. You can see those in this picture.

With the modified seat back in place. Looks pretty good, I think.

Center cushion removed to show step area.

This is a view of a cushion bottom. Each cushion has it's own base. I saved the plywood from the two access panels, epoxied both sides, then screwed them to the bottoms of the left and right cushions. Those pieces are sized so they're a tight fit in to the access panels, which holds the cushions in place. The center cushion is pretty well wedged in there, but I'll probably remove all three cushions when trailering.

Completed seat with all cushions in place.

I haven't had the boat out yet (week long trip coming up, we leave Sunday), but based on sitting on the seat and making vroom-vroom noises, I think it'll do the job. Currently in the storage space are two anchors, a 100' anchor line, a 50' anchor line, my tool/spare parts box and my flush hose. Still more room for ski lines and whatnot if needed.

SSMoose- feel free to ask questions. I'll help out if I can. It was not as hard as it looked. I did a lot of thinking about what I wanted the seat to look like and how to accomplish that, so it seemed to go pretty smoothly.
G

I have often thought about a similar setup but I have not had time to tackle it. I bought an extra used rear seat to try my ideas without destroying the original. This gives me some motivation and I may use some of your ideas if you don't mind.

Sledge-
It was a pretty straight-forward job. There are a couple of little things I discovered:
-I used a jigsaw to cut the Styrofoam seat. When you're cutting the seat back, the saw foot needs to be angled to compensate for the angle of the seat back so you get a nice cut. I didn't do this, and had to fill in with foam shims and construction adhesive.
-That same angled seat back, when in place, will rise up if you lean on it (when it's in the boat). I used those carpeted wooden blocks to keep it from moving.
-I found that the seat base I made wanted to slide around on the carpet. I screwed a couple of blocks on the front corners that wedge it in place. The wedges aren't visible once the base is in position on the boat.
Those are the big things I remember. The rest of it is just taking your time and thinking about what you want it to look like.
Good luck!
Greg